my code is as follow:

class FormFeedback(models.Model):
    _name = 'form.feedback'
    _description = "Form Feedback"

    feedback_type = fields.Char(string="Type", require=True)
    feedback_description = fields.Char(string="Description", require=True)
    feedback_date = fields.date(string="Date", require=True)
    obstetrics_feedback = fields.Many2one('ec.medical.obstetrics', string='Obstetrics')
    
    
    ------------------------------------------------------------------------------------------------------

class OehObstetrics(models.Model):
    _name = 'ec.medical.obstetrics'
    _inherit = ['ec.medical.patient.gfields', 'ec.medical.patient.summery']
    _description = 'Obstetrics of Patient'

    previous_obs_files = fields.One2many('ec.medical.obstetrics', 'obs_file_inverse', store=False,
                                         compute='fetch_previous_obs_files')
    obs_file_inverse = fields.Many2one('ec.medical.obstetrics')
    feedbacks = fields.One2many('form.feedback', 'obstetrics_feedback',string='Feedback')